I just bought a Moto x pure edition model XT1575 thru amazon. I purchased a sim card from republic wireless. I put the sim card in and attempted to install app thru the google play store. I then got the “this device is not compatible with this version” HELP! THIS IS VERY FRUSTRATING! I really wanted to sign up with republic wireless but I cannot get anyone to call me and fix this.

The other thing to check, once you’ve verified that your Moto X Pure is on Android 6.0 rather than 5.1.1 as suggested by @drm186, is to be certain you’re downloading the correct version of Republic’s app. There are two versions in Google’s play store. You want this one: Republic - Android Apps on Google Play.